1. Field of the Invention
The present invention relates to a screen printing apparatus, and more particularly to a screen printing apparatus which is structured so as to apply a creamed solder and an adhesive to a sheet of base plate on the assembly line, print a different pattern and further apply a printing agent such as a creamed solder, the adhesive and the like at a different thickness, at a stage of a printing process.
2. Description of the Prior Art
A base plate such as a printed board is fed to the next mounting process so as to be mounted with electronic parts thereon after being applied a creamed solder and the like thereto in accordance with a predetermined pattern by a screen printing machine.
Then, after mounting the electronic parts to the base plate, the adhesive is applied to the base plate or in some cases, the creamed solder is again applied to the base plate in accordance with another pattern, however, this operation can not be performed for printing by using a mask since the electronic parts are mounted on a surface thereof.
Accordingly, it has conventionally been unavoidable to perform the operation by using a nozzle. However, much labor is required for performing the operation under a state that a large number of electronic parts are mounted, so that a large time loss is caused. Further, in the case of applying the creamed solder in another pattern, it is necessary to again mount the electronic parts thereafter, so that a double labor is required.